PROJECT SUMMARY Adherence to antihypertensive medications remains unacceptably low despite decades of research. This is especially true in vulnerable populations (socioeconomically disadvantaged and/or minority) who simultaneously experience the highest rates of adverse hypertension-related sequelae (e.g. myocardial infarction, stroke), and have the lowest levels of adherence. Studies to date targeted at improving adherence, such as patient education and counseling, have yielded some success but are often resource-intensive and not scalable across institutions. Behavioral economic approaches have recently been developed to enhance medication adherence; these strategies aim to leverage innately human tendencies (such as overweighting of immediate benefits) in order to improve health behaviors. To date, several behavioral economic-based studies using a lottery incentive program (?regret lottery?) approach, whereby participants are encouraged to undertake healthy behaviors through the desire to avoid regret over losing financial incentives, have been promising. However, whether these incentives translate to sustainable behavior change in vulnerable populations is unclear. In this context we propose BETTER-BP (Behavioral Economics Trial To Enhance Regulation of Blood Pressure), a pragmatic randomized trial within the New York City Health and Hospitals (NYC-H+H) system, which is the largest public hospital system in the U.S. and serves a diverse and disadvantaged population. Our trial will recruit from 3 NYC-H+H ambulatory clinics, and will use a lottery incentive program to promote adherence to antihypertensive medication that will be delivered via smartphone for 6 months. Participants will be followed for a total of 12 months to examine durable effects. We will randomize 435 patients with hypertension determined to have poor adherence (<80% adherence with antihypertensive medication), in a 2:1 (intervention:control) ratio. In Aim 1 we will evaluate the effects of the incentive lottery on ambulatory systolic blood pressure (SBP) and adherence (good adherence defined by ?80% days adherent) between intervention and control arms at 6 months. We hypothesize that the incentive lottery will reduce SBP by ?10 mmHg compared with control, and that more participants receiving the lottery will be adherent. In Aim 2 we will examine durable effects of the lottery on SBP and adherence at 12 months. In Aim 3, we will analyze trajectories of adherence among participants assigned to the intervention group, as well as predictors of category membership. The PI for this project (Dr. Dodson) is a cardiologist and Early Stage Investigator with experience in cardiovascular epidemiology and clinical trials. Co-I?s are Dr. Troxel, a biostatistician and expert in behavioral economic clinical trials, and Dr. Schoenthaler, a behavioral scientist with expertise in adherence and patient engagement. The results could lead to sustainable and scalable strategies to improve antihypertensive adherence and BP control among socioeconomically vulnerable patients.